Impact testing apparatus



July 14, 1936. L. A. CURRIER IMPACT TESTING APPARATUS Filed Deo. 2o, 1929 v imleff AM'. 4MM-m.

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Patented July 14, 1936 PATENT OFFICE IMPACT TESTING APPARATUS vLeslie A. Currier, Claremont, N. H., vassigner to Sullivan Machinery Company, a corporation of Massachusetts Application December 20, 192,9,- Serial No. 415,554

5 Claims. '(Cl. 265-13) uring the effectiveness of a rock drill or similar' tool having a percussive motor. One obiiect of my invention'is to providean. improved apparatus' for determining the power fof a motor of the per'- cussive type. Further objects of my Vinvention will become apparent .in the course ci the ensuing description, and will be' more 'particularly pointed out in the accompanying claims..

Inone form, my invention may `comprise a receptable containing a gas, in combination with means `for indicating the degree of vcompression of the gas andmeans actuated by the percussive motor being tested for compressing said gas. It' desired, Vthe compressing means may be `a pump separate from the receptacle, for instance acyl.- inder and piston. In such casa. it is advantageous to use a liquid to transmit pressure yfrom'the. separate pump to theA receptacle containing thegas. A still greater advantage is obtained if the passage lfor liquid between the pump 'and the re- 1 ceptaclezrestricts ilow of liquid.

For purposes of illustration, one embodiment which my invention :assume is .disclosed lin the accompanying drawing in which,-

Fig. 1 is a View partially in side elevation, butY mainly centralsection, of testing apparatus vcooperating with a rock Ldrill -of the percusssive motor type.

Figi.'` 2 is a verticalv transverse 'section on line 2-2 of Fig.V 1.

Fig. 3 .is asimilar sectionzon line 3-3 of Fig. 1.

Fig. 4 :is a fragmentary plan view of Vone side.

of the horizontal cylinder and its support shown in Fig. 1.

This'illustrative embodiment of'my invention includes a receptacle B mounted on a bracket 1. In the particular `formshown in the drawing the receptacle 6 is a cylinder or pipe extending between an upper block 6 and a lower block 9, the bore of the receptacle 6 communicating at one end with a chamber I0 in the block 8 andat its other'end with a chamber l I in the block 9. 'An inlet pipe I2 controlled by a'valve I3 is connected to the chamberv l0 and is attached to supply gas, for example, air, from any suitable source. 'The `valve I3 may be closed when suiiicient gashas been introduced into the receptacle 6. A pressure gauge Hlis connected by a valve controlled conduit I5 with the chamber IIJ. A tube I6 of glassorrcther translucent material is disposed parallel to the receptacle 6 and is connected to the chamber I0 by an elbow Il and to the chamber II by `an elbow IB. A pipe mis-connected by a port 20 with the chamber II. The pipe I9 may include a coil to take up vibrations produced in the pumping mechanism next to be described. 5

The vmechanism so far described constitutes rin eiiect a liquid operated lpressure gauge having means for transmitting to it the forces to be measured and provided with means for effecting variation in a known manner -of its sensitivity.

The pumping mechanism mentioned is, in the particular form shown herein, of the cylinder and piston type, and pumps oil-'or other suitable liquid into the chamber II and then upwardly within the receptacle 6 land tube I-6 vuntil the gas contained within-the receptacle .and tube reach a pressure such that the percussive motor will no longer increase such pressure. The pumping mechanism rests. on a support 2I and is provided with va head 22 having a passage 23 to which an end of the pipe I9 is connected. A .back head 24., provided with an opening 25, is spaced from the head 22 and between the two heads extends a cylinder member 26. Bolts 2-'l secure the two heads to the base -2Iy and side rods 2la connect the heads together. A piston 28 is reciprocable withinthe cylinder 26 and is provided with a striking head 28 at its rear end. Twobolts 30 ex tend upwardly from kthe base 2| at a distance rearwardly from the back head 24. Av rock drill 3| having a cylinder 32 and side rods 33 may be disposed on the base 2I so that a striking member 34 which receives blows from the percussive motor of the drill may abut against the striking headY and drive the piston 28 forwardlly. The drill 3| may be clamped tothe base 2I by a horseshoe vshaped cross-piece 35 clamped underneath the heads of thetwo bolts 30.

In the operation of my improved measuring apparatus twoV methods may 4be followed. In either case the cylinder 26 and pipe 6 will be -lled with oilror other suitable liquid as through. the stand pipe 36, which is provided with a suitable .plug valve that may be closed only after the pipe is entirely filled thereby eliminating the 45 possibilityV of -an air .pocket therein.VV InV the first method, -in filling the spaces just mentioned it isk preferable that the piston -28 be in its extreme left-hand position and that pipe 6 `be filled to a given level which might be gaged by the level 50 of the liquid in the transparent gage tubeA I6 and its associated graduated scale 31,-this level being preferably zere. 'Ilo insure that thelpiston 28 isf its'extremez left-hand position and that .the air trapped in the pipe 6 above the liquid level is 55 under a predetermined pressure, air pressure may be admitted through pipe I2 until the pressure gage I4 indicates some predetermined pressure. Valve I3 is then closed and if desired the pressure gage I4 also may be closed 01T from the pipe 6 by its valved controlled conduit I5. Thus upon operation of the percussive motor 3l to be tested its hammer piston will impart blows to the member 34 which in turn will transmit the hammer blow forces to piston 28 and cause the same to move toward the right and through the medium of the oil compress the trapped air in pipe 6. During this compression the liquid level in pipe 6 and also gage 6 will move upwardly until the trapped air is compressed to a pressure where the force of the hammer blows is balanced at which time the liquid level will remain substantially stationary whereupon the reading on scale 31 may be taken. There are no perceptible fluctuations in the liquid level in pipe 6 or gage I6 because of the rapid succession of hammer bloWs imparted to: the member 34 and hence the reading on` scale 31 gives a substantially true index of the operation of the motor 3| being tested.

To test another motor and thus obtain a comparison, possibly with some desirable standard, the operation will be the same in that the initial liquid level in gage tube I6 will be brought to the same reading on scale 31 which was used with the previous test and also the same initial air pressure will be applied above the liquid level. With thi-s mode of operation there will be no errors due to having different volumes of trapped air for different tests.

In the second method of operation the necessity for obtaining the same initial liquid level in pipe 6 for each different test is eliminated, in that pipe 6 is filled to any level and any desired degree of air pressure is admitted through pipe l2 so as to insure that piston 28 is in its extreme left position, and that some initial pressure is applied on the system. The pipe I2 is then closed and the usual valved conduit I5 is opened, or is already open, whereupon operation of the hammer motor to be tested will cause transmission of pressure to gage I4 so that the indicating hand thereof will register the pressure-created by the hammer motor. Preferably the pipe I9 does not provide a passageway of too large a cross-section so that the oil is caused to be gradually forced through the same and thus contribute to the stability of operation.

It will be further understood that in case a small amount of oil should leak from the apparatus or should a ner adjustment be desired to obtain the initial Zero liquid level, the motor 3| and piston 28 may be moved to the right by tightening nuts 39 which are threaded on the extended portions of side rods 21a. These rods extend rearwardly through a cross member 40 disposed transversely of the motor and in addition each has nuts 4I for holding the cylinder heads- 22 and 24 independently of any adjustment of nuts 39. To allow adjustment of motor 3I to the left, nuts 39 and clamp 35 may be loosened whereby air pressure in cylinder 6 will move piston 28 and motor 3I to the left as nuts 39 are adjusted. If an excess quantity of oil is present, the liquid level also may be adjusted merely by slightly opening a drain cock 42.

Having once determined a-certain pressure increase or indication, on either the pressure gage I4 or liquid gage I6, to be the standard for a percussive motor of any given type, it is obviously a simple matter to compare such a standard motor with other motors of the same type as they are manufactured. My apparatus is of assistance therefore to manufacturers of tools which have a percussive motor and since my apparatus operates simply and expeditiously to indicate clearly the efficiency of the motor, it is obvious that I have provided a measuring apparatus which has wide usefulness.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. Apparatus for measuring the blows delivered by percussive motors including a receptacle, means for lling said receptacle with gas at different predetermined pressures, means for compressing said gas comprising a liquid piston and means for transmitting to said liquid piston the blows of a percussive motor, and means associated with said receptacle for enabling the notation of the degree of compression of the gas.

2, Apparatus for determining the blows delivered by percussive motors comprising a receptacle for containing gas, means for lling said receptacle with gas at different predetermined pressures, means actu-ated by a motor undergoing test for compressing the gas, and means for indicating the degree of compression of the gas.

3. Apparatus for measuring the blows delivered by percussive motors including, in combination, means to receive the blows of the motor to be tested, liquid means for transmitting the force of said blows, a gaseous column having means associated therewith for indicating the force of the blows and connected with said liquid force transmitting means, means for providing diiferent. initial pressure conditions in said column, and means for determining the exact nature of such conditio-ns.

4. Apparatus for measuring the blows delivered by percussive motors including, in combination, means to receive the blows of the motor to be tested, liquid means for transmitting the force of said blows, a gaseous column having means associated therewith for indicating the force of the blows and connected with said liquid force transmitting means, means for providing different initial pressure conditions in said column, and means for determining the exact nature of such conditions connectible with said column to permit observation of the conditions therein and having means for thereafter disconnecting the same from said column.

5. Apparatus for measuring the blows delivered by percussive motors including, in combination, means to receive the blows of the motor to be tested, liquid means for transmitting the force of said blows, Ya gaseous column having means associated therewith for indicating the force of the blows and connected with said liquid force transmitting means, means for providing different initial pressure conditions in said column, and means for determining the exact nature of such conditions including a calibrated pressure gage and a valved connectionbetween the same and said column.

LESLIE A. CURRIER. 

